Our laboratory has played a major role in the discovery and characterization of the neuronal antigen Neuron Specific Enolase (NSE) and its glial counterpart Non-Neuronal Enolase (NNE). We have utilized our specific NSE Antibody to develop a highly sensitive radioimmunoassay and immunocytochemical procedure to do both quantitative and qualitative studies at the basic and clinical level. For the past two years we have focused on clinical studies where we have shown that two neuro-endocrine neoplasms, oat cell lung cancer and pediatric neuroblastoma can be effectively monitored by measuring serum NSE levels. Serum NSE levels are highly elevated in both conditions, returning to normal during remission and rising again with relapse. Serum NSE determinations are rapidly becoming routine clinical procedures in both of these neuroendocrine neoplasms. Studies in 30 Alzheimer's disease patients have shown elevated serum NSE levels relative to age-matched controls. Basic studies have focused on the electron microscopic localization of NSE and on cloning of the gene for NSE so that the mechanisms controlling NSE synthesis can be studied.